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Author Topic: Thames Valley signalling problems - big delays - July 2014  (Read 87481 times)
Tim K
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« Reply #120 on: July 26, 2014, 10:16:41 »

I was at Paddington last night and it was the worst I'd ever seen.  I saw the mass scrum towards the 18:30 train and decided to get a coffee instead and wait for the 19:30 hoping services would be getting back to normal.  The 19:30 was announced a few minutes late on platform 1, we all rushed there only to find a completely full train with the doors locked!  I'm guessing it was an earlier service which had been "re-branded" as the 19:30, as other posters have commented there was a complete lack of information.  I got the 19:45 to Plymouth instead as most of the Reading bound commuters were still on platform 1 wondering what had happened and I changed trains at Reading to get to Swindon.

There were frequent announcements over the tannoys that customers for Reading were advised to get the train from Waterloo, but seeing the "delays of up to one hour" on SWT (South West Trains) website put me and I'm guessing a lot of other commuters off of that option.

Only bright side was that being one of the first onto the 19:45 (as the lights were off and the doors were locked until the last minute) I got a seat - which I promptly gave up to an elderly couple who were heading home from Belgium and had been travelling since 9am!
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Gordon the Blue Engine
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« Reply #121 on: July 26, 2014, 10:37:14 »

So what exactly is a lightening strike that affects miles of signalling? Is it a strike on the power supply to the signalling equipment (which presumably has surge protection), or on the lineside cables in the troughing (seems unlikely), or on the rails themselves which carry the track circuits? If the last, does replacing TC(resolve)'s by axle counters help to provide resilience against lightening strikes?  Maybe Electric Train or S&T (Signalling and Telegraph) Engineer can enlighten us.

edit - put "r" in toughing!
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Electric train
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« Reply #122 on: July 26, 2014, 11:19:23 »

So what exactly is a lightening strike that affects miles of signalling? Is it a strike on the power supply to the signalling equipment (which presumably has surge protection), or on the lineside cables in the troughing (seems unlikely), or on the rails themselves which carry the track circuits? If the last, does replacing TC(resolve)'s by axle counters help to provide resilience against lightening strikes?  Maybe Electric Train or S&T (Signalling and Telegraph) Engineer can enlighten us.

edit - put "r" in toughing!

The problem is lightening arresters have a voltage limit to what they can safely discharge to earth beyond which they themselves will flashover, there are a lot of circuits therefore a lot of lightening arresters all of which take time to check / replace; some are self resting others are sacrificial although if the lightening was severer enough even the self resetting ones will be toast .   

All sorts of kit can be damaged in the power supply chain, transformers, rectifiers even switchgear, cables particularly joints and terminations can flashover.  Find components that have obvious damage is the easy bit, only to find when systems are powered up something that looked ok fails and may be not straight away.

Lightening can hit the railway direct which is conducted along the rails and cables or it can be a nearby strike the resulting EMP (Electro Magnetic Pulse) which induces a voltage into the rails and cables which is conduct along the rails and cables in both cases for some considerable distance. 

Don't know to much about axel counters however at the end of the day they are still and electrical / electronic device therefore susceptible to direct strike or EMP.

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« Reply #123 on: July 27, 2014, 00:11:05 »

Regarding the problems on 25th July, it appears that the Cotswold Line was sacrificed with regard to trains to/from London.  Heaven knows what happened to all the intending passengers. According to Realtime trains nothing ran from Paddington through to the Cotswold Line after the 1421 until the 2148:

DOWN SERVICES
 
1552 PAD» (Paddington (London) - next trains)-WOS» (Worcester Shrub Hill - next trains) ^ CANCELLED (Started from Oxford at 1654 and appears to have been a HST (High Speed Train)).
 
1622 PAD-OXF» (Oxford - next trains) ^ CANCELLED.
 
1715 DID» (Didcot Parkway - next trains)- GMV -  started from Oxford at 1758 and terminated at Worcester Foregate Street.
 
1722 PAD-HFD» (Hereford - next trains) ^ CANCELLED.
 
1749 PAD-WOS ^ CANCELLED.
 
1822 PAD-HFD ^ CANCELLED.
 
1922 PAD-HFD ^ CANCELLED.
 
2022 PAD-GMV ^ CANCELLED (Started from Oxford).
 
2148 PAD-WOS ^ Departed 12 minutes late but was further delayed by signalling problems in the Radley area and arrived at WOS at 0045.  There were people on board who required onward transport from Worcester and the Train Manager came through to obtain details.
 
UP SERVICES.
 
1314 HFD-PAD ^ Probably terminated at Oxford.  Realtime Trains shows it as terminating at Didcot North Junction at 1543.  It then returned at 1643 to form the 1552 ex PAD starting at Oxford.  Perhaps, it went into Didcot Parkway station.
 
1426 GMV-PAD ^ Terminated at Oxford.
 
1553 MIM-PAD ^ Terminated at Oxford.
 
1532 GMV-DID ^ Terminated at Oxford.
 
1514 HFD-PAD ^ Terminated at Oxford.
 
1728 WOF-PAD ^ Terminated at Oxford.
 
1849 WOF-PAD ^ Ran through to Paddington arriving 41 minutes late at 2140.
 
1944 GMV-PAD ^ Started from Worcester F S.
 
2059 WOS-PAD ^ CANCELLED.
 
2151 HFD-PAD ^ Started from Great Malvern.

I have not studied what happened to Paddington to Oxford services, but I saw no evidence of any during the mid evening period when I was caught up in the disruption at Didcot Parkway and Oxford stations.  In fact, the only down FGW (First Great Western) trains I saw at Didcot were heading towards Swindon until a Turbo arrived from Reading to form the 2126 to Oxford.  This was to be delayed as well by signalling problems in the Radley area. A few CrossCountry trains went round the curve avoiding Didcot station.   
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a-driver
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« Reply #124 on: July 27, 2014, 09:19:37 »

So what exactly is a lightening strike that affects miles of signalling? Is it a strike on the power supply to the signalling equipment (which presumably has surge protection), or on the lineside cables in the troughing (seems unlikely), or on the rails themselves which carry the track circuits? If the last, does replacing TC(resolve)'s by axle counters help to provide resilience against lightening strikes?  Maybe Electric Train or S&T (Signalling and Telegraph) Engineer can enlighten us.

edit - put "r" in toughing!

The problem is lightening arresters have a voltage limit to what they can safely discharge to earth beyond which they themselves will flashover, there are a lot of circuits therefore a lot of lightening arresters all of which take time to check / replace; some are self resting others are sacrificial although if the lightening was severer enough even the self resetting ones will be toast .   

All sorts of kit can be damaged in the power supply chain, transformers, rectifiers even switchgear, cables particularly joints and terminations can flashover.  Find components that have obvious damage is the easy bit, only to find when systems are powered up something that looked ok fails and may be not straight away.

Lightening can hit the railway direct which is conducted along the rails and cables or it can be a nearby strike the resulting EMP (Electro Magnetic Pulse) which induces a voltage into the rails and cables which is conduct along the rails and cables in both cases for some considerable distance. 

Don't know to much about axel counters however at the end of the day they are still and electrical / electronic device therefore susceptible to direct strike or EMP.



What they believe happened is lightning struck 1L62 12:28 Swansea to Paddington.  This then fed into the tracks and basically toasted the signalling equipment in the area.
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« Reply #125 on: July 27, 2014, 14:27:00 »

I think that many commuters have experience in jobs/organisations where the level of service offered by NR» (Network Rail - home page) and FGW (First Great Western) would be completely unacceptable but many in the rail industry simply cannot see that the current service level is unacceptable and believe that down-time is just something that will happen on the railways - hence the often polarised views on sites such as this . 

To me the issue on Friday, and many of those previously, was not the trigger event e.g. lightning strike/points failure etc., but that the network has so many single points of failure.  Can you imagine the customer outcry if banking, mobile phone, supermarkets, gas pipelines, airlines, traffic lights etc. had a failure rate the same as the line between Paddington and Reading?  The attitude from FGW was "it was a lightning strike what do you expect us to do about that", to which my answer is "build into your network the fact that equipment will be struck by lightning and have a contingency plan", I can accept the network going dark for a short while but a predictable event causing disruption on the scale and with the duration of Friday night/Saturday morning surely cannot be viewed as acceptable by anyone?

In most industries you plan for key equipment failures and build in resilience, this is a concept that appears to be alien to the rail industry.  I'm sure the "experts" will be along to tell us why this is the case shortly, however, in the industries I have worked and consulted in there has always been those "experts" that have told us that we have to accept that some events are going to happen that will result in failure to provide service.  Almost without exception we have engineered solutions with resilience that ensure that there are no single points of failure.   Yes, you do get down-times but these are usually triggered when multiple trigger events coincide and almost never by a single predictable event.

Moving forward I believe two things need to change:

- The attitude and thinking from those in the rail industry who have "always done it this way" and that service outage is part and parcel of running a railway service
- Benefit analysis of investment cost of building in resilience vs. cost of putting right failure/reputational risk

For everyone who tells me it can't be done I bet we can find a network overseas where it is.....
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ChrisB
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« Reply #126 on: July 27, 2014, 14:33:07 »

If you don't mind paying fopr it all, of course it can be done.

But it'd be political suicide....
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« Reply #127 on: July 27, 2014, 14:48:43 »

That's exactly one of the "expert" responses we normally get, usually the first. When we do the analysis we normally we find we are already paying the cost of building in resilience, if not more, when we cost the impact of the down time.
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ChrisB
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« Reply #128 on: July 27, 2014, 14:53:23 »

Very different to finding the cost in hard cash (i.e. taxpayers money)
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« Reply #129 on: July 27, 2014, 15:10:48 »

You build a business case case based on investment, pay-back period, and reduced cost in the future. You are right a tough sell politically where anything that pays back beyond the current parliament is normally not viewed as positive. However, it can be done someone ran some numbers for HS2 (The next High Speed line(s)) and managed to build a business case for investment with payback over a much longer period than Reading to Paddington line would require.

I genuinely believe it is about mindsets.  Fifteen years ago I remember my tube journeys having a similar failure rate to what I experience now using FGW (First Great Western).  Management and had the same couldn't care less, like it or lump it, attitude as we currently see with FGW and NR» (Network Rail - home page). There has been a real attitude change there. Investment that someone had to build a business case for has happened. The failure rate is now much less than it was (although still higher than I would like).

Hopefully, the type of thinking I am describing was applied to the Crossrail and electrification planning....

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ChrisB
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« Reply #130 on: July 27, 2014, 15:22:20 »

Oh, I can clearly see where you are coming from....

BUT, it will take a physical load of ^billions to get to what you describe. And that can only be got in two ways - borrow it (and look where that gets us) or raise taxes. Political suicide either way
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ellendune
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« Reply #131 on: July 27, 2014, 15:36:12 »

You build a business case case based on investment, pay-back period, and reduced cost in the future. You are right a tough sell politically where anything that pays back beyond the current parliament is normally not viewed as positive. However, it can be done someone ran some numbers for HS2 (The next High Speed line(s)) and managed to build a business case for investment with payback over a much longer period than Reading to Paddington line would require.
By all means do the sums, but building a business case is not just playing with numbers till what you want adds up.  There is either a business case or there isn't.

BUT, it will take a physical load of ^billions to get to what you describe. And that can only be got in two ways - borrow it (and look where that gets us) or raise taxes. Political suicide either way

However if this is the case then I would be almost sure that there is no business case.

Unless of course we can innovate so that there is less kit out there to get struck by lightning. Perhaps once we get to in cab signalling it will be possible to reduce the risk.  Do axle counters (as opposed to track circuits) reduce vulnerability? 
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stuving
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« Reply #132 on: July 27, 2014, 15:44:03 »

Do axle counters (as opposed to track circuits) reduce vulnerability? 

Potentially yes. They are insulated from the track which is why they are immune to traction currents.

This is what NR» (Network Rail - home page) say about lightning:
Quote
    Lightning strikes

    How lightning strikes can cause delays - and what we're doing to reduce their effect

    Lightning strikes damaged rail infrastructure an average of 192 times each year between 2010 and 2013, with each strike leading to 361 minutes of delays. In addition, 58 trains a year were cancelled due to damage by lightning.

    Rails are made of steel which is an excellent electrical conductor; we make use of this by using the rails in ^track circuits^ to detect the location of trains.

    When lightning strikes a rail, the high voltage can damage this sensitive electronic signalling equipment. As our signalling system fails safe, when a component is damaged all signals in the area turn red and trains must stop.
    How we're reducing delays caused by lightning strikes
        We^re installing ^surge arrest^ equipment to prevent lightning strikes from damaging signalling equipment
        We're trialling a system which accurately identifies the location of lightning strikes almost immediately, enabling us to deploy staff to the site more quickly and reducing the impact on train services
        Using historic data, we predict which areas are at the most risk of lightning strikes and ensure that stores are fully stocked with parts which are likely to be damaged
        Until the damaged parts are replaced and tested, the signaller will keep trains moving by making direct contact with the driver of every train passing the affected area

As you can see, they identify track circuits as the big area of vulnerability. I reckon that electrification and the associated resignalling ought to improve that a lot.

Of course how axle counters and other kit is are made and installed could introduce new vulnerabilities.
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BBM
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« Reply #133 on: July 27, 2014, 15:48:09 »

BUT, it will take a physical load of ^billions to get to what you describe. And that can only be got in two ways - borrow it (and look where that gets us) or raise taxes. Political suicide either way

How many ^billions would it take for FGW (First Great Western) to simply improve their level of customer service? If there had been more staff available at PAD» (Paddington (London) - next trains) on Friday evening to look after passengers and provide as much information as possible it would have gone a long way to improving people's experiences.

And if it's the case that no information was available, how many ^billions would it take to improve that situation? From RTT» (Real Time Trains - website) it looks like the first stopper to TWY (Twyford station) on Friday evening eventually left at 2012. If FGW had said at 1730 that there would be no trains to TWY until after 2000 I would have gone away and come back again later instead of despairing and taking a taxi. Surely someone at NR» (Network Rail - home page) had a reasonable estimate of service resumption which they could have passed on to FGW?

I realise that things do go wrong which are out of the railway's control. Why should it be seemingly out of the railway's control to look after their passengers?
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ChrisB
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« Reply #134 on: July 27, 2014, 15:52:30 »

Of course how axle counters and other kit is are made and installed could introduce new vulnerabilities.

And surges when lightning strikes the overhead wires? (which conduct electricity so well that strikes are likely to be common)

BBM, how do you determine quickly how long a recovery will taker from a lightning damage? NR» (Network Rail - home page) need to get to site & assess the damage. Only then (and that could take the best part of an hour) might I be willing to agree with your paras above.

How much would it cost to have customer service teams on standby just in case?....be realistic. NR had a large team out at PAD» (Paddington (London) - next trains) on the night, but Friday nights are notorious for the number of pax travelling.
« Last Edit: July 27, 2014, 16:02:45 by ChrisB » Logged
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